This invention relates to an improved voltage transformer for a metal-encapsulated high-voltage switching apparatus of the type which includes a cylindrical sleeve forming a surface-type electrode disposed about a high-voltage conductor of the apparatus in conjunction with which a high-potential capacitor of a voltage divider is formed. Such a voltage divider also includes a low-potential capacitor, connected to the high-potential capacitor and to an amplifier and a load coupled to the amplifier output. In such voltage transformers, attachment of the sleeve to the metallic casing of the apparatus is unnecessarily complicated, thus increasing the manufacturing expenses incurred in producing such apparatus. A more simple arrangement for mounting the sleeve within the casing is therefore desirable.